Β-hemolytic Group Research Articles

Atypical spontaneous bacterial peritonitis linked to streptococcal toxic shock syndrome

A 59-year-old female patient with an unremarkable medical history presented with watery diarrhea, severe lower abdominal pain, and fever for approximately 7 days. Physical examination revealed a distended abdomen, bowel sounds were absent, and there was an acute abdomen with generalized guarding and significantly elevated inflammatory markers. Abdominal computed tomography showed significant ascites and signs of peritonitis. Exploratory diagnostics were indicated. A laparoscopy was performed, which revealed diffuse purulent peritonitis. Organ perforation or other reasons for a peritonitis were excluded. Bacteriological examination and blood cultures showed β-hemolytic group A streptococci, leading to the diagnosis of spontaneous bacterial peritonitis caused by streptococci. The patient was treated with antibiotics, progressively recovered, and was discharged symptom-free and without sequelae. Primary spontaneous bacterial peritonitis caused by Streptococcus pyogenes is a rare cause of acute abdomen. An early diagnosis and immediate antibiotic therapy are crucial for prognosis.

7-Year (2015-21) longitudinal surveillance of lefamulin in vitro activity against bacterial pathogens collected worldwide from patients with respiratory tract infections including pneumonia and characterization of resistance mechanisms.

Lefamulin (Xenleta™), a pleuromutilin antibiotic, was approved for the oral and IV treatment of community-acquired bacterial pneumonia (CABP) in adults in 2019/2020. This study evaluated the in vitro activity of lefamulin and comparators against 19 584 unique bacterial isolates collected from patients with community-acquired respiratory tract infections and hospitalized patients with pneumonia within the global SENTRY Antimicrobial Surveillance Program during 2015-21. Isolates were susceptibility tested by the CLSI broth microdilution method, and resistance mechanisms were investigated in isolates with elevated lefamulin MICs. Lefamulin exhibited potent antibacterial activity against the most common and typical CABP pathogens tested, including Streptococcus pneumoniae [MIC50/90, 0.06/0.25 mg/L; 99.9% susceptible (S)], Staphylococcus aureus (MIC50/90, 0.06/0.12 mg/L; 99.6% S), Haemophilus influenzae (MIC50/90, 0.5/2 mg/L; 99.1% S) and Moraxella catarrhalis (MIC50/90, 0.06/0.12 mg/L; 100.0% S). Potent activity was also observed against the less common pneumonia pathogens: β-haemolytic (MIC50/90 of 0.03/0.06 mg/L) and viridans group Streptococcus spp. (MIC50/90 of 0.06/0.25 mg/L) and Haemophilus parainfluenzae (MIC50/90 of 1/4 mg/L). Lefamulin's activity was not adversely affected by resistance to macrolides, penicillin, tetracyclines, fluoroquinolones and other resistance phenotypes. Non-susceptibility/resistance to lefamulin was rare and primarily determined by ribosomal protection through vga(A) variants in S. aureus, overexpression of AcrAB-TolC efflux pump in H. influenzae or modifications in L3, L4 and 23SrRNA in Streptococcus spp. Based on the coverage of the most important CABP pathogens and lacking cross-resistance, lefamulin may represent a valuable empirical treatment option for ambulatory and hospitalized patients with CABP, particularly in settings with high prevalence of resistance.

Oritavancin in vitro activity against Gram-positive organisms from European medical centers: a 10-year longitudinal overview from the SENTRY Antimicrobial Surveillance Program (2010–2019)

To assess oritavancin in vitro activity against clinically relevant Gram-positive pathogens in European (EU) hospitals, a total of 51,531 consecutive and unique clinical isolates collected in 2010–2019 were evaluated. All isolates were tested by CLSI broth microdilution methods. The key resistance phenotypes differed considerably between Eastern Europe (E-EU) and Western Europe (W-EU), respectively: methicillin-resistant (MR) Staphylococcus aureus 27.7%/22.9%; multidrug resistant (MDR) S. aureus, 19.7%/15.2%; MR coagulase-negative staphylococci, 77.3%/61.9%; vancomycin-resistant enterococci (E. faecium), 44.2%/20.9%; and MDR E. faecium, 63.8%/55.4%. There were no substantive differences in oritavancin minimum inhibitory concentration (MIC) values for the different species/organism groups over time or by EU region. Oritavancin inhibited 99.9% and 99.1% of all S. aureus and coagulase-negative staphylococci at 0.12 mg/L, respectively, and all isolates of E. faecalis and E. faecium at ≤0.5 mg/L. Oritavancin susceptibility rates against β-hemolytic and Viridans group streptococci isolates were 98.1% and 99.4%, respectively. Oritavancin had potent activity in vitro against this contemporary collection of European Gram-positive isolates from 2010 to 2019.

Most Common Causative Organism in Hand Abscess, Secondary to Puncture Wounds

Hand infections are frequently encountered problem by primary care doctors and orthopedic surgeons. Objective: To evaluate the frequency of common causative organisms in hand abscess, secondary to puncture wounds in patients. Methods: Descriptive cross-sectional study in the Emergency Services of plastics and hand reconstructive surgery at a Civil Hospital in Karachi, Pakistan from January to June 2022. A sample size of 156 was estimated. The Inclusion criteria of our study were Patients of age >18 years, and patients presenting with hand abscess secondary to puncture wounds. A Non-probability consecutive sampling technique was utilized to collect the data. Data were analyzed using SPSS version-23. Frequency and percentage will be computed for gender, diabetes mellitus, hypertension, location zone, and causative microorganism. Results: 156 patients were enrolled in our study out of which, 94 (60.3%) were male and 62 (39.7%) were females. The mean age of the patients was 59.7 years and the mean BMI was 32.3 kg/m 2.83(53.2%) patients had diabetes and 95 (60.9%) patients were hypertensive. The most common location zone of the abscess is Thumb & 1st web space (22.4%). The most common organism identified was Staphylococcus aureus (30.8%) followed by Streptococcus β-hemolytic group A (19.9%) and Staphylococcus coagulase-negative (14.1%). The least common organism was Klebsiella oxytoca (0.6%). Conclusions: The most common cause of hand abscess is staphylococcus aureus and puncture wounds result in hand abscess. Therefore, we conclude that in the cases of puncture wounds, physicians should timely assess the patients for the bacterial cause and treat accordingly to avoid the worst prognosis.

Biochemical and molecular identification of Gram-positive isolates with β-hemolysis activity isolated from the nasal swab of pigs during the human meningitis outbreak in Badung Regency, Bali-Indonesia.

Background and Aim:The nasal cavity of a pig serves as an entry point and a habitat for the colonization of commensal microbes and pathogenic bacteria. Based on biochemical and serological tests, Streptococcus b-hemolytic Group C was identified as the Gram-positive bacteria, which resulted in the 1994 outbreak and death of thousands of pigs in Bali. Furthermore, this agent is zoonotic and frequently results in the development of meningitis lesions in the infected pig. Recently, a meningitis outbreak in humans was also reported after the consumption of pig-derived foods at Sibang Kaja, Badung-Bali. This study aimed to identify and characterize Gram-positive β-hemolytic organisms collected from nasal swab of pigs from the outbreak area, as well as to compare API Kit and 16S rRNA gene analysis methods.Materials and Methods:This study commenced with the cultivation of two isolates, Punggul Swab Nasal (PSN) 2 and PSN 19, which were characterized by β-hemolysis activity. These samples were then conventionally and molecularly identified using Kit API 20 Strep and 16S ribosomal RNA (rRNA) gene primers, respectively.Results:Using the Kit API 20 Strep, both isolates were identified as Enterococcus faecium, which was previously classified as Group D Streptococci. Based on the 16S rRNA gene sequencing, PSN 2 and PSN 19 were molecularly confirmed to have 99 and 98.1% similarities with E. faecium (NR042054), respectively. Furthermore, both isolates share the same clade in the phylogenetic tree analysis.Conclusion:Using Kit API 20 Strep and 16S rRNA gene analysis, the PSN 2 and PSN 9 Gram-positive isolates with β-hemolysis activity from pig nasal swabs were identified as E. faecium.

Life-threatening complications of streptococcal sepsis: a PICU contemporary series

BackgroundLife-threatening streptococcal sepsis nowadays represents an uncommon event in previously healthy infants and children. Critically ill patients suffering from severe streptococcal sepsis complications may present with pre-antibiotic era clinical pictures and require a timely clinical approach to achieve restitutio ad integrum.ResultsWe report a series of four patient groups affected by an uncommon life-threatening streptococcal sepsis, each of them exhibiting some distinct features. Streptococcus Agalactiae sepsis was associated with cerebral thrombotic/ischaemic lesions, whereas severe cardiogenic shock was prominent in the Streptococcus Viridans group; Streptococcus Faecalis and β-hemolytic group A Streptococcus patients mostly reported lung complications.ConclusionsPrevious antibiotic treatments should not delay aggressive treatment in the intensive care setting. Early diagnostic suspicion, as well as appropriate and aggressive treatment provided within an intensive care setting are crucial for the clinical outcome.

Transcatheter closure of silent patent ductus arteriosus for prevention of endocarditis is justified

A diagnosis of ductal infective endocarditis (DIE) usually relies on the clinical histories of infectious syndrome, results of blood cultures and echocardiography. It remains a therapeutic challenge. The prognosis is still poor. Is the prevention of infective endarteritis a valid reason to always close the isolated silent PDA in childhood? The question is not yet eluded [1] , [2] , [3] , [4] . We present the case of six years old girl with DIE developed after dental procedure. The patient was managed by combined medical and early surgery with favorable evolution. A six year old girl was admitted to our service with tachypnea, fatigue and fever lasting for seven days. The patient had dental procedures few days earlier. The physical examination revealed a temperature at 40 °C and a left subclavian murmur. The acute phase marker levels were significantly elevated and β-hemolytic group A streptococcus was grown in his blood culture. Echocardiography revealed vegetations with the diameter of 10 mm on the left side of the PDA ( Fig. 1 ) with turbulent flow in the left pulmonary artery. Treatment with ceftriaxone 200 mg/kg/day and gentamycin 5 mg/kg/day was started then readapted according to antibiogram. The operation was performed on day 15 of antibiotherapy ( Fig. 2 a and b), whom was continued for 4 weeks. The fever did not return and the clinical course of the patient was stable; the final echocardiogram revealed the absence of left ventricular dilatation with a correct systolic function, normal pulmonary pressure. She was discharged four weeks after the surgical cardiac procedure. Infective endarteritis (IE) complicating PDA is very rare nowadays and the risk is very low especially in the industrialized world. Indeed, standardized management by a skilled multidisciplinary team with expertise in imaging, surgery and intensive care has proven to decrease mortality [3] , [4] , [5] , [6] , [7] . Primary prevention is vital. Even though it was not clear if the closure of a small PDA was beneficial, routine closure of any PDA in children and young adults appeared reasonable. The reasons for this recommendation included the risk of infective endocarditis and low-or-zero morbidity from closure, especially when using a transcatheter device [8] , [9] .

Diseases of the upper respiratory tract in pregnant women

Inflammatory diseases of the upper respiratory tract are extremely common, 6-15% of healthy people get sick every year. Pregnant women, due to physiological changes in the upper respiratory tract and a special immune state, get sick even more often.The purpose of the article is to provide doctors with basic information about the features of the course and treatment of the most common diseases of the upper respiratory tract during pregnancy.Prerequisite for the development of nasal congestion syndrome during pregnancy is an imbalance in the autonomic regulation of vasoconstriction and vasodilation of the vessels of the nasal mucosa and secretion of the nasal glands, the predominance of parasympathetic influences. The most common nosological causes of nasal breathing disorders are allergic rhinitis, gestational (hormonal) rhinitis and acute rhinosinusitis.The pathogenetic mechanism of gestational rhinitis is estrogen-mediated inhibition of cholinesterase, resulting in cholinergic vasodilation and increased secretion of mucous glands. The increase in circulating plasma volume and extravasal transudation, which is also due to the effects of estrogen on the vascular wall, contribute to pregnancy. Treatment is symptomatic (local decongestants, herbal secretolytics, sea water).Allergic rhinitis is based on IgE-mediated inflammatory process of the mucous membrane of the nasal cavity and paranasal sinuses. The most common causative allergens are plant pollen, spores of lower fungi, insect particles, animal epidermis, house dust mites. Treatment includes topical and systemic agents (glucocorticosteroids with low bioavailability, H1-histamine receptor blockers).Acute rhinosinusitis is an inflammation of the nasal mucosa and paranasal sinuses that lasts up to 12 weeks. In pregnant women, the development of the disease and its prolonged course is facilitated by frequent swelling of the nasal mucosa. The main causative agent of GDS are viruses (approximately 80% of cases). Evidence-based treatment includes irrigation therapy (symptomatic treatment of all forms of GDS), modern phytonutrient therapy using standardized BNO 1016 extract (for viral and post-viral MS, safe during pregnancy), mometasone furoate (nasal spray), anesthesia . Antibacterial drugs are indicated only for the treatment of bacterial rhinosinusitis.Acute tonsillitis is an inflammation of the tonsils with clinical symptoms that occur suddenly. Specific manifestations are sore throat (without acute shortness of breath), redness and swelling of the tonsils, often with layers, regional lymphadenitis; non-specific – fever, general weakness, malaise and pain in the joints and lower back. The clinical picture in pregnant women does not differ significantly. The severity of the disease and the probability of bacterial etiology is assessed on a special scale. Be sure to determine the presence of β-hemolytic group A streptococcus in the throat, depending on which antibacterial treatment is prescribed.

Severe Group A and Group B Streptococcus Diseases at a Pediatric ICU: Are they Still Sensitive to the Penicillins?

: Background: Group A β-hemolytic Streptococcus (GAS) and Group B streptococcus (GBS) are two common pathogens that are associated with many diseases in children. Severe infections as a result of these two streptococci are albeit uncommon but associated with high mortality and morbidity, and often necessitate intensive care support. This paper aims to review the mortality and morbidity of severe infection associated with GAS and GBS isolations at a Pediatric Intensive Care Unit (PICU).Methods: All children admitted to PICU of a teaching hospital between October 2002 and May 2018 with laboratory-proven GAS and GBS isolations were included.Results: There were 19 patients (0.7% PICU admissions) with streptococcal isolations (GAS, n=11 and GBS, n=8). Comparing to GAS, GBS affected infants were younger (median age 0.13 versus 5.47 years, 95% CI, 1.7-8.5, p=0.0003), and cerebrospinal fluids more likely positive (p = 0.0181). All GAS and GBS were sensitive to penicillin (CLSI: MICs 0.06 – 2.0 μg/mL), with the majority of GAS sensitive to clindamycin and erythromycin, and half of the GBS resistant to clindamycin and erythromycin. Co-infections were prevalent, but viruses were only isolated with GAS (p=0.024). Isolation of GAS and GBS was associated with nearly 40% mortality and high rates of mechanical ventilation and inotropic supports. All non-survivors had high mortality (PIM2) and sepsis scores.Conclusions: Severe GAS and GBS are rare but associated with high mortality and rates of mechanical ventilation and inotropic supports in PICU. The streptococci are invariably sensitive to penicillin. The high PIM2 and Sepsis scores suggest that prompt recognition of sepsis and the timely judicious institution of antibiotics and intensive care support may be life-saving for these devastating infections.

Comparative genomic analysis of Streptococcus dysgalactiae subspecies dysgalactiae, an occasional cause of zoonotic infection

Streptococcus dysgalactiae comprise two subspecies. Typically, S.dysgalactiae subspecies equisimilis (SDSE) are large colony β-haemolytic Group C and Group G streptococci that cause pharyngitis, skin and soft tissue infections in humans. On the other hand, S.dysgalactiae subspecies dysgalactiae (SDSD) are classically described as α-haemolytic Group C streptococci that are animal pathogens. We compared the genome sequences of five S.dysgalactiae isolated from four cases of bacteraemia in women with breast cancer, and one from fish meat. One human isolate was SDSE, all other isolates were SDSD. Zoonotic SDSD infection may be under-recognised because of lack of patient and clinician awareness, and failure to distinguish SDSD from SDSE in the routine lab. The possibility of zoonotic SDSD should be suspected in patients with bacteraemia and ascending cellulitis of the upper limb with a history of handling raw fish and meat.

Prothrombotic and Proinflammatory Activities of the β-Hemolytic Group B Streptococcal Pigment

A prominent feature of severe streptococcal infections is the profound inflammatory response that contributes to systemic toxicity. In sepsis the dysregulated host response involves both immunological and nonimmunological pathways. Here, we report a fatal case of an immunocompetent healthy female presenting with toxic shock and purpura fulminans caused by group B streptococcus (GBS; serotype III, CC19). The strain (LUMC16) was pigmented and hyperhemolytic. Stimulation of human primary cells with hyperhemolytic LUMC16 and STSS/NF-HH strains and pigment toxin resulted in a release of proinflammatory mediators, including tumor necrosis factor, interleukin (IL)-1β, and IL-6. In addition, LUMC16 induced blood clotting and showed factor XII activity on its surface, which was linked to the presence of the pigment. The expression of pigment was not linked to a mutation within the CovR/S region. In conclusion, our study shows that the hemolytic lipid toxin contributes to the ability of GBS to cause systemic hyperinflammation and interferes with the coagulation system.

380. Characterizing Host Factors, Treatment Strategy, and Clinical Outcomes of Group A Streptococcus Orthopedic Infections

BackgroundThe annual incidence of invasive β-hemolytic group A streptococcus (GAS) infections in the United States is approximately 3.8 cases per 100,000 patients with 10–30% mortality. But data in GAS orthopedic infections is limited. We sought to characterize patient factors, medical and surgical management, and clinical outcomes from GAS orthopedic infections at our medical center.MethodsA total of 12 patients with GAS orthopedic infections (necrotizing fasciitis, osteomyelitis, prosthetic joint infection, septic arthritis, or tenosynovitis) from July 2017 and March 2019 were included. Medical records were reviewed for site of positive GAS culture (blood, wound, joint fluid, or tissue cultures), demographics, comorbidities, surgical management, and antibiotic regimen and duration. The primary outcome was cure at 90 days defined as clinical improvement without recurrent or new infection, or further surgical or medical management at 90 days after treatment completion. The secondary outcome was erythrocyte sedimentation rates (ESR) before and after treatment.ResultsThe median age of the 12 patients was 56 years (range 3–75); 58% were female and 58% had a body mass index ≥30 kg/m2. The median Charlson comorbidity index score was 3 (range 0–7) with 58% having diabetes mellitus. Two patients had either rheumatoid arthritis or monoclonal gammopathy (Table 1). Most patients had severe infections; 33% with necrotizing fasciitis and 25% with orthopedic implants. All patients had an elevated initial ESR, including 75% with ESR >40 mm/h. 92% required surgery, including 42% amputations and 17% prosthesis removals. Patients were mostly treated with β-lactams and vancomycin (92%); only 50% received clindamycin or linezolid. Most patients (75%) required at least 2 weeks of antibiotics. Five patients (42%) were not cured at 90 days, and 1 died of infectious complications (Table 2).ConclusionSevere GAS orthopedic infections necessitate both surgical management and prolonged antibiotics. 42% of our patients were not cured at 90 days and most eventually required amputation. Toxin mediators, clindamycin and linezolid, were underutilized. Chronic suppressive antibiotics should be considered for patients with orthopedic implants, especially those with durable immune suppression. Disclosures All authors: No reported disclosures.

β-Hemolytic Streptococcus anginosus subsp. anginosus causes streptolysin S-dependent cytotoxicity to human cell culture lines in vitro

ABSTRACTBackground: Streptococcus anginosus subsp. anginosus (SAA) is one of the opportunistic pathogens in humans that inhabits the oral cavity. The type strain of SAA, NCTC10713T, showed clear β-hemolysis on blood agar plates, and the sole β-hemolytic factor revealed two streptolysin S (SLS) molecules. SLS is well known as the peptide hemolysin produced from the human pathogen S. pyogenes and shows not only hemolytic activity on erythrocytes but also cytotoxic activity in cell culture lines in vitro and in vivo, such as in a mouse infection model. However, no cytotoxic activity of SLS produced from β-hemolytic SAA (β-SAA) has been reported so far. Objective and Design: In this study, the SLS-dependent cytotoxicity of the β-SAA strains including the genetically modified strains was investigated in vitro. Results: The SLS-producing β-SAA showed cytotoxicity in human cell culture lines under the co-cultivation condition and it was found that this cytotoxicity was caused by the SLS secreted into the extracellular milieu. Conclusion: The results from this study suggest that the SLS produced from β-SAA might indicate the cytotoxic potential similar to that of the SLS from S. pyogenes and the SLS-producing β-SAA would be recognized as “a wolf in sheep’s clothing” More attention will be paid to the pathogenicity of β-hemolytic Anginosus group streptococci.

Evaluation of Antibiotic Treatment on the Duration of Hospitalization of Patients with Erysipelas and Bacterial Cellulitis.

IntroductionErysipelas and bacterial cellulitis are two of the most common infectious skin diseases. They are usually caused by the β-hemolytic group of Streptococcus, and less frequently by other bacteria. The objective of the study was to assess the factors affecting the length of stay of patients admitted to hospital with erysipelas or bacterial cellulitis.MethodsThe study was based on the retrospective analysis of medical records of patients diagnosed with erysipelas or bacterial cellulitis. Selected clinical features of the disease, the results of additional tests, the treatment used, and the time of hospitalization were analyzed. Among an initial group of 78 pre-identified patients, 59 subjects aged from 32 to 89 years were included in the final analysis. The time spent in the hospital and the number of antibiotics necessary to cure the patient were chosen as the parameters of treatment efficacy.ResultsThe average duration of stay in a hospital was 7.0 ± 2.9 days and was slightly longer for women than for men. Patients with chills on admission, with coexisting chronic venous insufficiency of the lower limbs, and with anemia were hospitalized for a significantly longer period than those without these conditions. A combination therapeutic regimen of amoxicillin + clavulanic acid was the most commonly used treatment option, and this therapy was linked with shortest duration of stay in the hospital; the length of hospital stay was significantly longer for those patients receiving cephalosporins or clindamycin as treatment. The combination therapy of amoxicillin + clavulanic acid as treatment option was also least often associated with the need to use other antibacterial agents.ConclusionsBased on our evaluation of 59 subjects with either erysipelas or bacterial cellulitis, combination therapy with amoxicillin + clavulanic acid appears to be linked with the shortest stay in the hospital. We suggest that this combination therapy should be considered as a first-line treatment for patients hospitalized due to erysipelas or bacterial cellulitis, if other factors did not preclude the use of this therapy.

79-Year-Old Man With Shortness of Breath and Fevers

79-Year-Old Man With Shortness of Breath and Fevers

Oritavancin in vitro activity against gram-positive organisms from European and United States medical centers: results from the SENTRY Antimicrobial Surveillance Program for 2010–2014

The in vitro activity of oritavancin was assessed against 44,715 gram-positive pathogens causing infections in European and United States (US) hospitals (2010–2014). There were no substantive differences (>±2-fold dilution) in oritavancin MIC50 or MIC90 values for different species/organism groups over time or by region. Oritavancin (99.9% susceptible) showed modal MIC, MIC50, and MIC90 results of 0.03, 0.03, and 0.06–0.12 mg/L when tested against Staphylococcus aureus, regardless of methicillin susceptibility, year, or region. Coagulase-negative staphylococci from the US and Europe demonstrated equal MIC50 values for oritavancin (MIC50, 0.03 mg/L). Oritavancin inhibited 99.9% of Enterococcus faecalis and all E. faecium at ≤0.5 mg/L, including vancomycin-resistant isolates. Oritavancin exhibited MIC50 results of 0.03 and ≤0.008 mg/L when tested against β-hemolytic and viridans group streptococci isolates, respectively, regardless of geographical region. Oritavancin maintained potent activity in vitro against this contemporary collection of European and US gram-positive isolates over 5 years (2010–2014).

In Vitro Activity of Tedizolid against Gram-Positive Cocci Isolates from Patients Hospitalized with Pneumonia in the United States and Europe, 2014-2016

Objectives: Tedizolid and comparator agent in vitro activities were assessed against clinically relevant gram-positive pathogens causing pneumonia in patients in European and US hospitals. Tedizolid was approved in the United States, Europe, and other regions to treat adults with acute bacterial skin and skin structure infections (ABSSSIs) and is being evaluated for treating nosocomial pneumonia. Methods: A total of 6,019 unique clinical isolates deemed to be responsible for community-acquired (CAP) and healthcare-associated pneumonia (HCAP), including hospital-acquired (HAP) in hospitalized patients, were included. A separate analysis included the HAP subset. Isolates originated from 33 and 30 institutions in Europe and the United States, respectively, between 2014 and 2016. Results: No substantive differences in tedizolid MIC values were found for the different species/organism groups over time or by geographic region. Isolates causing HAP showed slightly decreased activity to comparator agents compared to CAP/HCAP isolates. Tedizolid (100.0% susceptible) showed MIC50/90 results of 0.12/0.12 mg/L (US) and 0.12/0.25 mg/L (Europe) when tested against S. aureus HAP isolates, regardless of methicillin susceptibility or year of isolation. Coagulase-negative staphylococci from the United States and Europe (MIC50, 0.12 mg/L) demonstrated identical MIC50 values for tedizolid. Tedizolid exhibited MIC50 results of 0.25 mg/L and 0.12 mg/L when tested against β-hemolytic streptococci and viridans group streptococci isolates, respectively, regardless of geographic region. Conclusions: Tedizolid had potent activity in vitro against this contemporary collection of European and US gram-positive pneumonia isolates that was sustained over a period of 3 years (2014–2016).

Group G Streptococcus Induces an Autoimmune Carditis Mediated by Interleukin 17A and Interferon γ in the Lewis Rat Model of Rheumatic Heart Disease.

Acute rheumatic fever and rheumatic heart disease (ARF/RHD) have long been described as autoimmune sequelae of Streptococcus pyogenes or group A streptococcal (GAS) infection. Both antibody and T-cell responses against immunodominant GAS virulence factors, including M protein, cross-react with host tissue proteins, triggering an inflammatory response leading to permanent heart damage. However, in some ARF/RHD-endemic regions, throat carriage of GAS is low. Because Streptococcus dysgalactiae subspecies equisimilis organisms, also known as β-hemolytic group C streptococci and group G streptococci (GGS), also express M protein, we postulated that streptococci other than GAS may have the potential to initiate or exacerbate ARF/RHD. Using a model initially developed to investigate the uniquely human disease of ARF/RHD, we have discovered that GGS causes interleukin 17A/interferon γ-induced myocarditis and valvulitis, hallmarks of ARF/RHD. Remarkably the histological, immunological, and functional changes in the hearts of rats exposed to GGS are identical to those exposed to GAS. Furthermore, antibody cross-reactivity to cardiac myosin was comparable in both GGS- and GAS-exposed animals, providing additional evidence that GGS can induce and/or exacerbate ARF/RHD.

Draft Genome Sequence of Streptococcus dysgalactiaesubsp.equisimilis Strain C161L1 Isolated in Vellore, India.

ABSTRACTStreptococcus dysgalactiae subsp. equisimilis belongs to the β-hemolytic group C and G pyogenic group of streptococci. Here, we report the draft genome of the S. dysgalactiae subsp. equisimilis strain C161L1 from Vellore, a region in southern India with a high incidence rate of S. dysgalactiae subsp. equisimilis infection. This genome is 2.1 Mb long, with a 39.82% G+C content, and encodes 2,022 genes.

Pyogenic Sternoclavicular Arthritis Caused by Streptococcus agalactiae in an Elderly Adult with Diabetes Mellitus

Pyogenic Sternoclavicular Arthritis Caused by <i>Streptococcus agalactiae</i> in an Elderly Adult with Diabetes Mellitus